The exponential growth in the demand for higher bandwidths and increased data transfer rates has accelerated the deployment of optical networks in building a communication infrastructure. An optical fiber is typically fabricated from glass or plastic that is capable of propagating light or an optical signal (in the form light pulses) along its length with little attenuation compared to wired or wireless media, thereby enabling the signal to travel over longer distances and at higher bandwidths.
An optical fiber may be typically classified into two types—a single mode fiber (also referred to as a monomode fiber) and a multimode fiber. A single mode optical fiber typically restricts the propagation of light along the fiber core to a single mode (or transmission path), and a multimode fiber is a fiber that supports the simultaneous propagation of multiple modes (or transmission paths) since it has a larger core diameter compared to the optical wavelength as well as the single mode optical fiber. That is, a multimode fiber is an optical fiber that is designed to carry multiple light rays concurrently, each at a slightly different reflection angle relative to the axis of the optical fiber core. Multimode fiber transmission is typically used for applications covering relatively short distances because the modes tend to disperse over longer lengths, thereby causing signal distortion (this phenomenon is referred to as modal dispersion). Specifically, modal dispersion is the temporal spreading of the bits due to varying paths and arrival times of the pulses at the end of the fiber. Modal dispersion adversely affects the bandwidth carrying capacity of the network. The distortion is caused as a result of the propagation velocity of the optical signal being different for all modes (or paths) within the multimode fiber. A single mode fiber may be used for communications over longer distances.